Pontoise, Cadastre Napoléonien Limit (1815)

The commune of Pontoise is covered by the Napoleonic cadastre in 16 section sheets, all at 1:1250 scale. The sheets have been digitized by the Archives départementales du Val-d'Oise which keeps the originals. Each sheet has been trimmed and then recalibrated in relation to the Bd Topo of the IGN. A reasoned geometric recalibration, based on georeferencing and intended to correct the topometric inaccuracies of the document was carried out with the aim of obtaining a visual correspondence of the objects between the document and the current reference frames (Bd Topo, Open street map, current Cadastre base). The set of 16 sheets was then digitally assembled to obtain a single document offering continuous coverage of the entire municipality. The 16 georeferenced documents as well as the cadastral mosaic are distributed in the form of a georeferenced file in the WGS84-Pseudo Mercator (EPSG3857) projection system in JP2000 format (downloadable document) compatible with most spatial data management tools or in the form of data streams that can be integrated directly into these same tools. The Napoleonic Cadastre is a mapping operation decided in 1807. It was the first systematic operation on a French scale, with the objective of "measuring more than one hundred million parcels, classifying them all according to the degree of fertility of the soil, evaluating the taxable product of each of them, and gathering the parcels that belong to each owner" (Gaudin Law 1807). This vast and highly codified operation (cadastral code of 1808) was completed in the 1850s. For each commune, registers and an atlas composed of sheets at 1:250 (sometimes 1:500 or 1:200) referencing all of the land entities was executed. The Napoleonic Cadastre is a reference document for the study of pre-industrial spaces since it records the state of development of the territories at the beginning of the 19th century and is, by its overall topometric quality, generally quite accurate geometrically. It is also systematic in its content: plots, roads, odonyms, toponyms, hydrological network, buildings... etc. It can therefore easily be set in a current reference frame with margins of error that are sometimes small (these margins generally depend on the topographic environment: the rougher the territory, the less accurate it is. For Pontoise, the overall margin of error is about 2 m). Its qualities also make it possible to make the link with older documents whose shapes, often still present in the cadastre, can be transferred at sight into the geometric space of the Napoleonic period, which is itself easily "calibrated" in a current geometric space. This document has been vectorized manually (L. Costa) to be able to be processed spatially. A transformation was also carried out to obtain a layer on the parcels and their status, namely: built, light built, communication, Hydro, Parcel

庞托伊市镇地处拿破仑时期的地籍图覆盖范围内，共分为16张分幅图，比例尺均为1:1250。这些图幅已被瓦尔德奥塞尔省档案馆数字化，并保留有原始资料。每张图幅均经过裁剪，并参照IGN的Bd Topo进行了重新校准。基于地理定位的合理几何校准，旨在纠正文档的地籍不准确性，以实现文档与当前参考框架（Bd Topo、Open street map、当前地籍基准）中对象的视觉对应。16张图幅随后被数字化拼接，形成一个覆盖整个市镇的单一文档。16个地理参照文档以及地籍镶嵌图以WGS84-Pseudo Mercator（EPSG3857）投影系统中的地理参照文件形式（可下载文档）或数据流形式分发，这些数据流可以直接集成到大多数空间数据管理工具中。拿破仑时期的地籍图是1807年决定的一项测绘操作，它是首次在法国范围内进行的系统性操作，旨在“测量超过一亿个地块，根据土壤肥力程度对所有地块进行分类，评估每个地块的纳税产品，并收集属于每个所有者的地块”（1807年高丁法）。这项庞大且高度规范化的操作（1808年的地籍法典）于19世纪50年代完成。对于每个市镇，都编制了登记册和由1:250（有时为1:500或1:200）比例尺的图幅组成的图集，这些图幅参考了所有的土地实体。拿破仑时期的地籍图是研究前工业空间的重要参考文件，因为它记录了19世纪初领土的发展状态，且由于其整体的地籍质量，在几何上通常相当精确。其内容也具有系统性：地块、道路、街名、地名、水文网络、建筑物等。因此，它很容易被纳入当前参考框架中，误差范围有时很小（这些误差通常取决于地形环境：地形越崎岖，其精确度越低。对于庞托伊而言，总体误差约为2米）。其品质还使得可以将其与较旧的文档建立联系，这些文档的形状（通常仍存在于地籍图中）可以直观地转移到拿破仑时期的几何空间中，而拿破仑时期的几何空间本身也易于在当前几何空间中进行“校准”。该文档已由L. Costa手动矢量化，以便进行空间处理。还进行了一种转换，以获得地块及其状态的图层，即：建筑、轻型建筑、交通、水利、地块。